Birds are a group of warm-blooded, egg-laying vertebrates that belong to the class Aves. They are characterized by several distinctive features, including:

• Feathers for flight
• Light, hollow bones for increased mobility
• A beak or bill instead of teeth
• A large, well-developed brain
• The ability to lay eggs with hard shells

 Birds are found all over the world and come in a wide variety of shapes, sizes, and colors. Some common examples of birds include:

• Pigeons
• Sparrows
• Eagles
• Falcons
• Owls
• Parrots
• Chickens

Birds play important roles in their ecosystems, serving as pollinators, seed dispersers, and predators. They also have a significant impact on human societies, as many are domesticated and used for food, sport, and as pets.